Combined gas turbine power system using catalytic partial fuel oxidation

ABSTRACT

A gas turbine power system for generating energy by means of a gas turbine cycle, wherein heat energy is more effectively used by burning the exhaust gases ( 109 ) and the partial oxidation of said exhaust gases ( 109 ) is achieved by means of a hypostoichiometric amount of air and steam fed into a catalytic reactor ( 107 ) to form a first oxidation stage followed downstream in said turbine ( 103 ) by additional oxidation occurring in a power turbine ( 104 ) or downstream therefrom, said power turbine being in turn arranged downstream from the catalytic reactor ( 107 ). Catalytic partial oxidation may be performed using a supply of an initiating agent, particularly hydrogen. The method is remarkable in that the hydrogen fed into the reactor inlet through an injector ( 113 ) is provided by recycling part of the effluent from the reactor, the power turbine or a reforming reactor for reforming part of the fuel gas with a large excess amount of steam for performing catalytic partial oxidation.

TECHNICAL FIELD

The present invention relates to a thermal energy system comprising atleast one gas turbine intended to generate mechanical and/or electricalenergy by operating a gas-turbine cycle in which exhaust gases of thecycle having a certain amount of energy capable of beneficiation, inparticular mechanical and/or thermal beneficiation, are produced.

TECHNOLOGICAL BACKGROUND

The use of conventional gas turbines for the proposed industrialapplications is well known. Thus, when a cycle comprising one or moregas turbines is placed upstream of an existing steam cycle of a powerstation, the overall energy efficiency of a conventional power stationmay go from 0.4 to 0.45 at the cost of extensive modification of thesteam cycle, in particular by the addition of economizer exchangers.However, this technique proves to be expensive and only justifiable ifthe cost of the fuel itself is high. What is more, this techniqueinvolves an appreciable reduction in the useful power of the steamcycle. This results in only a modest overall gain in power, which foreconomic reasons is often unsatisfactory.

Another technique involves heat/force cycles, in which the gas turbinedelivers mechanical energy and the exhaust gases deliver heat which canbe exploited in various forms. In the case of a conventional gasturbine, this technique may prove to be useful when the necessarythermal energy is at low temperature, generally below 600° C. On theother hand, this technique is not applicable when the thermalrequirement is at a higher temperature level, in some cases evenmarkedly higher, as is the case for instance in cement works, glassworksand steelworks or in certain furnaces. These plants, upstream of whichthe gas-turbine cycle may be applied, are all provided with heatregenerators for reheating the combustion air, this heat no longer beingable to be recovered after the modification.

The conventional gas-turbine cycle involved in heat/force combinedsystems comprises an air compressor, a combustion chamber with a largeexcess of air and a turbine which generates the mechanical power.Downstream of the turbine, only the heat from the exhaust gases can berecovered.

Yet another technique involves combined cycles consisting of gasturbines and steam turbines of specific design. Their efficiency iscurrently between 0.5 and 0.53.

Even though conventional combined systems are operational, problems ofimplementation remain.

In so-called partial-oxidation systems, combustion is certainlycomplete, but staged. Firstly, partial oxidation is carried out, usingair in substoichiometric quantity and steam, in a catalytic reactorwhich replaces the combustion chamber of the conventional gas-turbinecycle. Next, the combustion is completed downstream in the power turbinebefore the thermal energy of the exhaust gases is used.

The principles of a partial-oxidation gas turbine have already beenpresented earlier, but the arrival of nuclear power stations and otherfactors, such as the possibility of supplying with natural gas, have notencouraged its development. Moreover, it would also seem from the priorart that the technological elements essential for improving theapplication of these principles were not forthcoming.

STATE OF THE ART

The publications mentioned below should be considered: “Cycle de turbineà gaz comportant un réacteur d'oxydation partielle catalytique de gaznaturel, son application dans les systèmes énergie-chaleur” by J.Ribesse at the 8th World Energy Conference in Bucharest from Jun. 28 toJul. 2, 1971 and in Gas Wärme International, Vol. 20-7/6 July and August1971; “Cycle combiné avec réacteur à oxydation partielle du combustible”by J. Ribesse, A. Jaumotte and A. De Goeyse, Entropy, 1976 and “TheIsotherm Partial-Oxidation Gas Turbine” by J. Ribesse, December 1990, inthe European Journal, Vol. 36, No.1, pages 27 to 32. It follows fromthese publications that the principle of partial oxidation consists incarrying out a catalysed exothermic reaction on the fuel, such asnatural gas, with compressed air under substoichiometric conditions anda limited amount of steam, so as to reach a predetermined reaction-gastemperature selected for the gas-turbine cycle.

This results in a reaction gas composed of CO, H₂, CO₂, H₂O, CH₄, N₂ andfuel. The reactions involved are:

CH₄+2O₂+8N₂→CO₂+2H₂O+8N₂ (exothermic)

CH₄+½O₂+2N₂→CO+2H₂+2N₂ (exothermic)

CH₄+H₂O→CO+3H₂ (endothermic)

Belgian Patent No. 769,133 describes a machine using specific elements,namely two compression stages and a catalytic partial-oxidation reactorproducing a combustible gas which is expanded in the power turbine withintermediate injection of water and steam. This exhaust gas can beconsumed in a thermal application benefiting from its enthalpic content.The process used involves the use of machines of a specificconstruction, such as turbines and compressors, the specific elements ofwhich are not, however, described.

Belgian Patent No. 1,003,760 describes a gas turbine system designedspecifically for partial oxidation. For this purpose, it comprises acompressor adapted so as to have a higher pressure level, a catalyticreactor and a turbine providing isothermal expansion by the effect ofgradual internal combustion by means of the air for cooling the turbineblades. This futuristic system will be able to be implemented only afterthe systems described in Belgian Application 09500879 and in the presentpatent application have been applied in more directly realizableassemblies.

In the aforementioned patent, the more specific means of the inventionare not described either.

The systems briefly described in the aforementioned Patents BE-769,133and BE-1,003,760 have a major drawback as they do not allow theavailable commercial gas turbines to be (re) converted. Thisconsequently requires the use of machines which are not produced at thepresent time and which thus have to be specifically developed, therebyinvolving very considerable investments.

Belgian Patent No. 1,004,714 describes the structure of apartial-oxidation gas-turbine cycle. For this purpose, a catalyticoxidation reactor is provided. The reactor contains reforming catalyst,a booster-ejector and a system for ignition and for temperaturemaintenance at stoppage. Fitting it to existing turbines is presented inthe case of the use of a pressure ranging from 50 to 60 bar and the useof the cooling air as oxidant in order to obtain expansion in the gasturbine at a constant temperature.

Moreover, the aforementioned Patent BE-1,004,714 deals briefly, and in atheoretical manner, with two of the three applications of partialoxidation which are described below, namely the conversion ofconventional gas turbines and the constant-temperature expansionturbine, of specific design.

Thus, in general, problems of, for instance, implementing each of theaforementioned patents remain.

SUBJECT OF THE INVENTION

The object of the invention is to remedy the aforementioned drawbacksand to provide a solution appropriate to the problems resulting from theforegoing with regard to the state of the art.

The system according to the invention is intended to be applicable inall energy systems which comprise a cycle consisting of one or more gasturbines, whether this cycle is combined with a steam-turbine cycle orwith thermal beneficiation of the effluent of the gas-turbine cycle.

Thus, the first subject of the present invention is the procedure forincreasing the power of a thermal power station, which procedure iscommonly called repowering. The present invention also relates toparticular aspects of the use of this technology in the applicationsmentioned above, especially energy systems which involve a gas-turbinecycle combined with beneficiation of the thermal energy of the exhaustgases of this cycle. This beneficiation is achieved either bycomplementary generation of mechanical energy (cycles comprising one ormore gas turbines and steam turbines) or by cogeneration, i.e.heat/force combined generation. These various systems are generallyreferred to as combined energy systems.

Moreover, the present invention also aims to provide complementarytechnological means for applying catalytic partial oxidation, thesebeing applicable in all combined energy systems which comprise a cycleconsisting of one or more gas turbines.

SUMMARY OF THE INVENTION

The invention consists of a combined energy system comprising at leastone gas turbine intended to generate energy by operating a gas-turbinecycle. In the latter, exhaust gases are produced which have a certainamount of thermal energy associated with complementary energyconversion. The aforementioned gas turbine is a partial-oxidation gasturbine. The system comprises an air compressor, a catalyticpartial-oxidation reactor carrying out the reaction:

C_(n)H_(m)+n/2 O₂+N₂→n CO+m/2 H₂+N₂

with production of a combustible gas at a high and controlledtemperature, and a drive turbine. The system is distinguished by thepartial oxidation being carried out in the said catalytic reactor bymeans of air injected in substoichiometric quantity and of steam, so asto form a first oxidation step, which is subsequently completeddownstream of the turbine by additional oxidation in a power turbine ordownstream of the latter, the said power turbine itself being placeddownstream of the said catalytic reactor. The system is alsodistinguished by conjoint beneficiation of the said thermal energygenerated by combustion of the exhaust gases.

Thus, the system according to the invention firstly allows commercialgas turbines of the aeronautical type or, in general, industrial gasturbines operating in a combustion mode without excess air to be adaptedso as, for a given machine, to improve the thermodynamic performance ofthe cycle and to increase the mechanical power available. It allowsenergy recovery in the secondary cycle of heat/force combined systems tobe improved, the adapted turbine delivering a high-temperaturecombustible gas.

The invention is aimed at applications such as, on the one hand,increasing the power and performance of the energy cycles ofconventional steam-cycle power stations and, on the other hand,heat/force cycles in which the thermal secondary cycle may be carriedout at any temperature up to 1300° C., therefore allowing the use ofcogeneration to be extended to many industrial thermal processes.

Secondly, the invention will allow future isothermal gas turbines to beconstructed and operated.

The performance improvement results from better exploitation of thethermodynamic properties of the gas-turbine cycle by avoiding the energyloss in conventional cycles which is due to the use of a large excess ofair. This is because it is possible to obtain the same temperature atthe inlet of the expansion turbine using air in substoichiometricquantity, where the temperature is compatible with the bladingconstraints.

The reaction gas obtained by partial oxidation is an inflammable gaswhich has a lower specific weight than the combustion gas and whichcontains either no oxygen or practically no NO_(x), in whichNO_(x)=aNO+bNO₂; this type of reaction is widely known in themanufacture of synthesis gas.

By comparison with known gas turbine systems, and for the same driveturbine, the mechanical energy developed by the power turbine is higherin the case of the invention, and the energy absorbed by the compressionof the air is reduced. The useful mechanical energy is thereforesignificantly increased in two respects, as much as being doubled.

In Table 1 below, A indicates the conventional case while B indicatesthe partial-oxidation case.

TABLE 1 A B Volumetric ratio (gas + air)/air 1.02 1.6  Density of thegas 0.98 0.7  Power developed by the turbine 1.0  1.15 Power absorbed bycompression 0.65 0.45 Useful mechanical energy 0.35 0.70 Composition ofthe gas 14% O₂ fuel

Described below are the specific technological aspects of the inventionfor implementing the principle of catalytic partial oxidation of thefuel so that the reaction produces the desired temperature level, whichcannot damage the blades of the gas turbines, without involving a verygreat excess of air which limits the performance of the thermal machinesinstalled downstream.

Implementing partial oxidation makes it possible to improve theperformance of the operational energy systems. By remedying theinadequacies of the above-mentioned prior art, the invention allows theindustrial-scale implementation of partial oxidation to be madeeffective and operational in energy systems. This is the case with therepowering of existing steam-cycle thermal power stations. This is alsothe case with the adaptation of existing cogeneration-integratedgas-turbine cycles. Again it is the case for the isothermal-expansionturbines of the future. In fact, it may conceivably be possible toachieve an efficiency of approximately 0.6 as a result of significantprogress, for instance, in the high-temperature withstand capability ofmaterials.

The present invention applies the principle of partial oxidation, on theone hand, to existing systems involving aeroderivative and industrialturbines, and, on the other hand, to specific gas turbines to bedesigned. By virtue of the present invention, combined cycles with avery high efficiency, ranging up to 0.63, may be constructed. Thus, theinvention consists of a system allowing effective and operationalimplementation of partial-oxidation turbines.

More particularly the invention makes it possible to adapt commercialaeronautical-type or industrial-type gas turbines, respectively, tooperation in a combustion mode without excess air, so as to improve thethermodynamic performance of cycles for converting the energy in fuelsinto mechanical or electrical energy. In addition, the invention makesit possible to design, construct and operate future gas turbines,especially isothermal gas turbines. Thus, the invention providesadditional innovative technological elements for implementing partialoxidation.

In addition, the present invention aims to solve two primary problemswhich confront flameless catalytic partial oxidation, namely of reachinga satisfactory initiation temperature and the possibility of carbondeposition.

In accordance with this invention, the presence of a suitable quantityof an initiator, advantageously hydrogen, in the process flux at theinlet of the partial-oxidation reactor helps to solve the aboveproblems. In addition, it provides a complementary degree of flexibilityin respect of the control and operability of the entire system. Thishydrogen comes from an external source if it is economically availableon the site or from the system itself. In this case, there are twoalternatives: either partial recycling of the gases collected downstreamof the reactor or an innovative combination of a partial-oxidation gasturbine and a small so-called “reforming” reactor which exchanges heatindirectly with the effluent from the power turbine.

The reactions involved in the partial oxidation of a gaseous fuel takeplace at different rates, these being characterized by differentactivation energies. It follows that the temperature profiles aredifficult to control and therefore that thermal stresses are difficultto avoid in the catalytic masses, the period of use of which will beappreciably reduced. The catalysts are in this case rendered friable,just as they could be by deposition of carbon within the pores of thecatalyst. This additional problem. Thus, by using successive layers ofcatalysts of different type and/or different activity, the temperatureprofiles are fully controlled and the risk of local runaway of thereactions is prevented.

In the partial-oxidation turbines of the future, in particular those ofthe “isothermal” type, there will be the additional problem of thecombustion of the effluent of the partial-oxidation reactor inside theactual power turbine using air, in particular using at least the air forcooling this turbine. The aforementioned additional problem is solved byvirtue of the invention by this complementary oxidation which may becarried out on an industrial scale by coating the blades of the gasturbine with a catalytic alloy. This may be carried out, in particular,by electrodeposition or by plasma.

When the partial oxidation of fuel is carried out in a gas-turbine cycleand including an air compressor, the latter is oversized. The excesscompressed air can be expanded in a corresponding turbine with asignificant part of the energy used for compressing it being recovered.The performance of the cycle can be markedly improved if this excess airis preheated before being expanded in the turbine. The heat will besupplied in an effective manner by indirect exchange with the flue gasesfrom the combustion of part of the exhaust gases of the power turbine orby direct combustion of the combustible gas with the air to bepreheated. According to the present invention, this heat can also besupplied from a hot source available on site.

Thus, the improvement in performance resulting from better exploitationof the thermodynamic properties of the gas turbine cycle is basicallyrendered technologically achievable by the presence of hydrogen at theinlet of a catalytic oxidation reactor and by the use of severaldifferent catalytic masses.

Furthermore, in an advantageous embodiment of the invention, the bladesof the turbine downstream of the reactor are provided with a catalyticcoating, where appropriate with the air being preheated—the preferredmode.

Other advantages and features of the present invention will be describedbelow using exemplary embodiments illustrated by the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a diagrammatic sectional view of a basic turbine.

FIG. 2 represents a first embodiment of the system according to theinvention with adaptation of an aeroderivative turbine.

FIG. 3 represents an enlarged detail of FIG. 2, showing a preferredbooster-ejector and a preferred reactor shape.

FIG. 4 illustrates a view similar to FIG. 3, showing a variant of thebooster-ejector.

FIGS. 5 and 6 each illustrate variants of the catalytic reactor with,respectively, noble-metal gauzes and a fixed bed consisting of catalystgranules.

FIG. 7 illustrates a diagrammatic sectional view of a conventionalindustrial turbine.

FIG. 8 illustrates a preferred way of adapting an industrial gas turbineaccording to a second embodiment of the system according to theinvention.

FIG. 9 illustrates an enlarged detail of a preferred embodiment of thereactor of the system according to FIG. 8.

FIGS. 10 to 12 illustrate the mode of conversion of the silo-typecombustor, with two conversion variants.

FIGS. 13 to 15 illustrate conversion modes of existing peripheralcombustors and, respectively, two conversion variants.

FIG. 16 illustrates a view similar to FIGS. 1 and 7 of apartial-oxidation turbine of a specific design in a third embodiment ofthe system according to the invention.

FIGS. 17 to 19 represent diagrammatic views showing the operation of thefirst embodiment of the system according to the invention, similar toFIGS. 1 and 2, in three successive initiator-injection modes.

FIG. 20 represents a diagrammatic view of a variant of the secondembodiment of the system according to FIG. 8.

DESCRIPTION OF THE INVENTION

The elements for implementing partial oxidation according to the presentinvention are described below for each of the respective applicationsgiven by way of preferred example.

FIGS. 1 and 7 show existing commercial gas turbines. FIG. 1 illustratesmore particularly the case of an aeronautical turbine to which a powerturbine has been added. FIG. 7 represents an industrial gas turbine.

FIGS. 2 to 6 are intended to demonstrate the characteristics of theinvention in respect of the first application described below ofadapting aeroderivative turbines to the partial-oxidation technology,both for the repowering of conventional thermal power stations and forheat/force cogeneration applications.

FIGS. 8 to 15 demonstrate the conversion of industrial turbines in orderto incorporate the technology of partial oxidation, which conversion isintended to improve combined energy systems, thus forming the secondapplication according to the invention described here.

FIG. 16 illustrates the incorporation of the technology according to theinvention in gas turbines of a specific design, forming the thirdapplication described.

FIGS. 1 and 2; 7 and 8, as well as 16, aim to demonstrate thecharacteristics of the invention. These show a one-stage compressor 101,as in FIGS. 1 and 2, or alternatively a two-stage compressor, asillustrated in FIG. 16, a combustion chamber 102 with a large excess ofair, a drive turbine 103 and a power turbine 104, an alternator 5, acatalytic reactor composed of an inert layer 171 and an active layer172, a filter 8 and exhausts 109 directed towards a steam cycle ortowards another enthalpy beneficiation means. A system for ignition andfor temperature maintenance at stoppage is also provided. The saidreaction is preferably initiated without a flame and with a minimum flowrate of steam, thus avoiding carbon deposition.

The applications mentioned below have in common most of thetechnological elements, both structural elements and functionalimplementation elements, with, in some cases, specific aspects for thevarious applications of the present invention, in particular thecatalyst 170, 270, 370, the partial-oxidation reactor 107, 207, 307 andthe flexibility in terms of the oxidant at the inlet of the catalyticreactor 107, 207, 307. If the pressure in the latter is too low, abooster-ejector 106, 206, 306 is provided, this serving in all cases asa mixer, otherwise exploiting the higher pressure of the combustiblegas, with control of the system on the basis of a mathematical model.Furthermore, a method of fitting the various elements according to theinvention to existing units, so as to form a high-performance system,even when starting with existing units, is proposed. This thus allowsrecovery from these units under satisfactory conditions. As a result,there is the possibility of advantageously achieving considerablesavings and of reducing the pollution from industrial or dischargesites.

The technological elements described below are to be considered withinthe scope of the present invention either by themselves or by their usewithin applications of implementation of partial oxidation in combinedenergy cycles or in heat/force cogeneration units.

The catalytic means used in the partial-oxidation reactor 107advantageously consist of impregnated metals on porous supports 173 soas to provide the reactions of partial oxidation of the fuel with steamand air or gases expelled by a high-pressure gas turbine 103 into theaforementioned partial-oxidation reactor 107. Thus, the following may beused: nickel on activated alumina, Ni/Al₂O₃, preferably with aconcentration of between 3 and 15%; platinum on zirconium oxide Pt/ZrO₂forming a preferred composition with a concentration of between 0.1 and1%, as it generates very little carbon deposit; Pd/ZrO₂ or Pt-Rh/ZrO₂.Alternatively, the said catalytic means may also consist of metal gauzescomposed of the above metals, especially Pt, Pt-Rh and Pt-Zr.

Moreover, the active porous support of the catalyst 172 and the inactivelayer 171 are advantageously honeycomb one-piece components 173 withinternal channels 174, as illustrated in FIG. 3, or are in the form ofmonotubular or multitubular granules with a smooth external surface 177,178 or monotubular or multitubular granules with a fluted externalsurface 179, as in FIG. 6, the multitubular form being preferred. Thepartial-oxidation reaction catalyst support is applied to the gasturbines with stability and heat-shock-resistance properties in thetemperature range going from 600 to 1000° C., not generating solidparticles, and producing low pressure drops.

The catalyst support consists of alumina or of refractory metals, whereappropriate in alloy form, such as nickel-chromium. In the case ofactive alumina, other metal oxides, such as oxides of magnesium or ofsilicon, may be added. For particular applications, the catalyst supportmay be in the form of hollow rings or of cylinders which are crenelatedor pierced with holes.

The reactors 107, 207, 307 are adapted to the applications, inparticular to aeronautical-type, industrial or specific-design gasturbines, respectively. Downstream of an aeroderivative turbinedelivering the oxidant, the reactor is in the form of a horizontalcylinder, as illustrated in FIG. 2. The aforementioned reactor 107 isshown in FIG. 3 in the form of two successive layers 171, 172, only oneof which, the downstream layer 172, comprises catalyst. The reactor mayalso be in the form of a vertical cylinder of the silo type or maycontain a series of catalytic metal gauzes 176 perpendicular to thedirection F of the stream of reaction gases, as illustrated in FIG. 5.The cylindrical metal casing 175 is lagged or protected thermally by adouble-walled casing through which the inlet stream to be reheatedflows.

The reactor described in document BE-1,004,714 can also be used withinthe context of the present invention, particularly when it is filledwith a specific catalyst, as defined above. Furthermore, the devices 206for making the reaction gases flow radially across the inactive layer271 and the specific catalyst 272 also form part of the invention, asillustrated in FIGS. 8 to 12. Whenever it is crucial for the pressuredrop across the catalytic bed 207; 271, 272 to be minimal, the latterdevices 206 are preferred.

The reactor 207 illustrated in FIG. 8 is filled with the specificcatalyst described above. This form of the reactor 307 is also appliedin the case of the specific machines illustrated in FIG. 16, whichcomprise in particular a compressor 310 having two stages 311, 312.

The axial horizontal cylindrical form, using a one-piece catalyst 172with a honeycomb shape 173, is preferred in the case of repoweringthermal power stations, as illustrated in FIGS. 2 and 3.

The silo forms, using metal gauzes 176 or granules of catalyst 180, arepreferred in the case of adapting existing industrial gas-turbinecycles. These forms are not illustrated as the structures of theexisting combustion chambers 202 which work with a large excess of airare used in this case and are adapted to flameless oxidation.

The axially symmetrical shapes of the mixer booster-ejector 106 areillustrated in FIG. 3. The booster-ejector 106 may be made from severalnozzles housed in cylindrical casings fastened in a ring configurationwith annular inlet and outlet manifolds.

The oxidant, injected into the partial-oxidation reactor 107, consists,in the case of the repowering of thermal power stations in FIG. 2, bythe effluent of a turbojet. In the case of adapting an existingindustrial gas turbine according to FIG. 8 or one to be manufacturedaccording to FIG. 16 for partial oxidation, the oxidant advantageouslyconsists of the effluent from the air compressor 201 or 310,respectively.

FIG. 3 shows a diagram of the system. A turbojet delivers the oxidantfor the reactor by burning and A expanding gas with compressed air inlarge excess. The burners of the combustion chamber 102 are suitable forgas. The booster-ejector 106 with its defined shape exploits thepressure of the combustible gas fed at this point in order to increasethe pressure of the mixture with respect to that of the oxidant. Thepartial-oxidation reactor 107 contains a catalyst and a support selectedfrom those which were specified above. A filter 8 for retaining carbonor coke and catalyst dust is placed so as to be readily removable. Acommercial power gas turbine 104, for completing the overall gas-turbinecycle particular to this application, drives an alternator 5 or amechanical machine and delivers a combustible gas to the exhaust 109.The enthalpy of the latter will be subsequently utilized in the thermalpower station, the boiler of which will not have to undergo expensivemodifications because of the temperatures achievable by combustion ofthe exhaust gases 109 of the power turbine 104.

The description below is more detailed and is intended to demonstratethe characteristics of the invention with regard to FIG. 1.

A turbojet engine is composed of an air compressor 101, a battery ofcombustion chambers 102, in which chamber or chambers the fuel is burntwith a large excess of air from the compressor 101, so as to achieve atemperature compatible with the system, and a high-pressure driveturbine 103 delivering the mechanical energy absorbed by the compressor101, these two machines being fastened to the same common shaft 51.

The hot gases ejected by the high-pressure turbine 103, for example at650° C., are available at a residual pressure of between 3 and 5 bar.

In existing conventional systems, as illustrated in FIG. 1, the reactiongases are then expanded in the power turbine 104 and escape therefrom ata low pressure and at a temperature of between 400 and 500° C. Thispower turbine 104 drives a mechanical or electrical machine 5. Theworking power represents only approximately one third of the total powerdelivered by the overall expansion of the gases, the remaining twothirds being intended to drive the compressor 101. The exhaust gases 109contain between 13 and 16% oxygen, on account of the large excess of airused in the combustion, as well as a large quantity of toxic gases suchas NOx. The specific power of a conventional gas turbine is quitelimited. This specific power is represented by the ratio of theavailable useful mechanical energy to the amount of gas conveyed in thecycle.

The present invention enables the performance of known systems to besubstantially improved by considerably increasing the specific power,which is generally doubled, and by drastically limiting NOx emissions,which are reduced almost to zero on leaving the reactor. It also makesit possible to obtain unequalled performance within the context ofincreasing the power of steam-type thermal power stations without havingto adapt or convert the thermal cycle of the units in question.

Referring now to FIGS. 2 and 3, the invention suitable for the turbosetsdescribed comprises the use of a number of booster-ejectors 106 ofspecific shape which are supplied with high-pressure fuel, such asnatural gas, for example, at between 30 and 50 bar, and withhigh-pressure steam. These static devices suck in the gases containingoxygen in excess from the high-pressure turbine 103. They ensure uniformmixing of the oxidizing gas of the fuel with the steam so as,subsequently, to carry out an exothermic partial-oxidation reaction.They make it possible to recover the compression energy of the lattertwo fluids by increasing the pressure of the mixture, relative to thatof the oxidant. One particular form of the booster-ejector 116, 126according to the invention is shown in FIGS. 3 and 4.

It comprises a pipe 113, taking the fuel and the high-pressure steaminto a circular internal duct. The latter distributes the fluids in aninjector having a toroidal shell 115, in the form of truncated sectors,widening out gradually and having a reduced section 119, at which thespeed of the fluid is close to the speed of sound. The section 119 thengradually increases downstream. By virtue of this device, the efficiencyof recovery of the potential energy of the high-pressure fluids isoptimized.

The booster-ejector 126 may also be constructed as in FIG. 4 by means ofa central element 127 which is hemispherical in shape and extended by athroat 128 formed by a slightly divergent cone extended by an invertedcone 129, the external part being formed by a divergent truncated cone.

The invention also encompasses any other shape of booster-ejectorexploiting the kinetic energy of the gases in the context of repoweringthermal power stations.

The gases in the mixture, which are ejected from the booster-ejectors106 at high speed, then advantageously pass through a catalytic bed 107consisting of a block of specific catalyst 173 in the form of ahoneycomb. The specific catalyst produces neither dust nor free carbon,its particular shape ensuring flow with a low pressure drop. It isintended to stabilize the fuel partial-oxidation reactions, whichreactions produce a combustible gas at a controlled temperature ofbetween 700 and 1000° C., for example 900° C. A quantity of steam isinjected for the purpose of preventing soot from being formed.

One particular form of catalytic mass is shown by the references 171 and172 in FIG. 3. The proposed catalyst 170 according to the invention isformed by the juxtaposition of elements composed of channels 174 with asquare section, having dimensions of between 1 and 5 mm, with the lengthof an element between 100 and 300 mm. These elements consist of athin-walled rigid support, which are resistant to thermal shocks andimpregnated with a catalyst composed as described above. The supportsfor the catalysts have a high specific surface area. They are based onactivated alumina in the case of Ni, in particular between 3 and 15% byweight, and based on zirconium oxide in the case of platinum, inparticular between 0.1 and 1% by weight. The said non-active mixed part171 of the catalytic reactor consists of the non-impregnatedaforementioned support the said part 171 serving to distribute thereaction gases uniformly and to prevent the exothermic reaction fromstarting inside the booster-ejector 106.

According to the invention, other forms of catalytic reactors and othercatalytic masses are also provided, as indicated below by way ofpreferred examples.

The catalytic element illustrated in FIG. 5 is composed of a number ofgauzes 176 made of platinum, rhodiated platinum, Pt-Zr alloy, orpalladium (these being described below).

FIG. 6 illustrates a reactor 181 in the form of an enlarged cylinderfilled with granules 180 of partial-oxidation catalyst. The granules 180have a cylindrical shape 177, a hollow cylindrical shape 178 or a flutedshape 179.

The preferred catalyst is formed with a support 175 made of refractoryor metallic material, with nickel as the active material, on activatedalumina, or with platinum or palladium as the active material, onzirconium oxide.

The invention also encompasses any other embodiment of an associableform of catalytic reactor in the case of repowering a thermal powerstation.

On leaving the catalytic reactor 107, the gas passes through ahigh-temperature filter 8, intended to collect the particles which couldbe accidentally entrained, and/or a thin layer 187 of support which hasno active material and is intended to collect the entrained activeelements.

Next, the gas flows into the power turbine 104 which drives a generatoror a mechanical machine.

The power turbine is a well-known machine. Within the context of theinvention, provision is made to operate the machine at a moderatetemperature so as, in a preferred method of implementing the invention,to dispense with the systems for cooling the turbine blades. However,under certain conditions it will be necessary to provide coolingcircuits and, in this case, to inject steam instead of air into them.

At the outlet 109 of the power turbine 104, the gas expelled at lowpressure and at a temperature ranging from 550 to 600° C., in thedirection indicated by an arrow E, is a combustible gas which can supplya conventional thermal unit such as a boiler of a conventionalsteam-type thermal power station or an industrial thermal equipmentitem, or else any type of industrial boiler or furnace operating at anytemperature, as in a cement works, a glassworks or a steelworks.

TABLE 2 Industrial Invention turbine without converted Type of gasturbine according to turbine Conventional conversion the inventionThermal unit MWe 210 250 240 power Gas turbine power MWe 2 × 25 *    57** 130 Total power MWe 260 307 370 without degradation Fuel consumptionMWth 577 697 787 Net power MWe  10  57 120 increase Conversion    0.44   0.44    0.47 efficiency NOX mg/m³ 100  10 5 to 10 Cost of high lowmoderate converting the thermal cycle * Use of two gas turbines ** Asingle gas turbine of the same type to be adpated

Table 2 gives, by way of indication, the performance characteristics ofan aeroderivative gas turbine, adapted according to the invention topartial oxidation and applied to the repowering of a steam-type thermalpower station having a net power of 250 MWe.

The thermal systems, which generally comprise heat regenerators, mustnot be modified. This advantageously results in the adaptation costsbeing therefore very limited. In addition, the operation is reversibleat any moment, thus making it possible to return to the prior situation.

The process according to the invention has a particularly beneficialtechnical and economic advantage, especially for the example illustratedby the numbers in the table. It is apparent that the specific power ofthe turbine is more than doubled, as indicated previously. Furthermore,a significant gain, namely more than 22%, in power of the power stationis obtained. This value should be seen in relation to that for theconventional gas turbine, which is only 10%. In addition, a very lowconversion cost is also obtained and the production of NOx is virtuallyeliminated.

The gas turbine of aeroderivative origin, in the case of the invention,requires no conversion.

The second application relates to the conversion of conventionalindustrial gas turbines.

It is possible to convert any conventional gas turbine to partialoxidation according to the invention in the context of the mentionedindustrial applications relating to turbojets. However, this adaptationrequires modifications to be made to the original gas turbine, asillustrated in FIGS. 10 to 12.

The industrial gas turbine consists of an assembly comprising an aircompressor 201, one or more combustion chambers 202, as illustrated inFIG. 7, in each of which the fuel is burnt with a large excess of air,and an expansion turbine 203 delivering the mechanical energy absorbedby the air compressor 201 and by a receiving machine 205, such as analternator.

Implementation of partial oxidation according to the invention involvesthree major modifications and performance improvements described below.

The first modification consists in replacing the combustion chambers202, which equip the gas turbine, by a partial-oxidation reactor 207, asillustrated in FIG. 8. This reactor 207 comprises one or morebooster-ejectors 206 supplied with high-pressure fuel, such as naturalgas for example, and with steam. The catalytic reactor 207 is providedwith a peripheral form and contains a specific catalyst in the form of ahoney-comb, in order to ensure that it is sufficiently rigid and has alow pressure drop.

According to one particular embodiment of the invention, theaforementioned booster-ejector 206 provided in the reactor 207 isradial, as shown in FIGS. 8 and 9, and consists of an injector having atoroidal shell 215 supplied with pressurized steam and fuel. Thebooster-ejector 206 comprises a throat 212 ensuring a flow speed closeto the speed of sound. The section of the booster-ejector 206 increasesin the direction of flow F so as to recover the compression energy.

Another form of booster-ejector comprises a battery of radially orientedelements.

The catalytic reactor 207 consists of an assembly of catalytic elementsin the form of a honeycomb, the elements of which consist of rectangularchannels having a dimension of, for example, 1 to 5 mm each side. Thecatalytic reactor 207 is therefore produced in the form of a ringsurrounding the gas turbine.

The catalytic elements are divided into two parts 271 and 272, asillustrated in FIG. 9. The elements 272 are impregnated with a catalyticmass consisting of activated alumina and of nickel, preferably between 5and 15%, or with other active materials mentioned above.

On the other hand, the elements 271 are not impregnated with a catalyticmass. They are intended to distribute the gas mixture uniformly over thecatalytic surface and also to prevent the exothermic reactions startingin the booster-ejector 206.

Other forms of partial-oxidation reactor may be used, also depending onthe original shape of the combustion chambers 202.

Example 1: a form of silo 212, as illustrated in FIGS. 11 and 12,replacing, according to the invention, that illustrated in FIG. 10. Inthis case, it is preferred to use a reactor 217 in the form of tworeversed cones, containing catalyst in the form of a honeycomb held inplace by meshes, as illustrated in FIG. 11. These reactors 217 alsocontain a peripheral booster-ejector 206, in FIG. 9, and a toroidalinjector 215 supplied with pressurized gas.

Another form of vertical reactor 227 is shown in FIG. 12 and comprises aperipheral compressed-air supply, a mixer-ejector 226 and a layer ofpartial-oxidation catalyst 272 as used in chemistry for secondaryreforming. In this case, a flame 230 is produced at the outlet of theejector 226.

Example 2: a battery of cylindrical combustors placed obliquely allaround the gas turbine illustrated in FIG. 13. The combustors arereplaced by catalytic partial-oxidation reactors 237 as shown in FIGS.13-15 and they include a peripheral compressed-air supply. Thebooster-ejector devices supply non-inflamed mixture to the catalyticmasses 273, in the form of a honeycomb, as in FIG. 14, or according tothe loose reforming catalyst 274, as illustrated in FIG. 15.

After leaving the catalyst 272, the gases pass through ahigh-temperature filter 8 or 208 intended to collect accidentallyemitted particles.

The precise dimensions of the reactor 207 according to FIG. 8 aredetermined by the characteristics of the gas turbine which is to beconverted to partial oxidation.

The reaction gas produced at the defined temperature passes through theexpansion turbine 203, generating mechanical energy in greatly increasedquantity compared to the initial situation.

The air compressor of a conventional gas turbine outputs too high a massof air to ensure operation in partial-oxidation mode. Thus, in thesecond modification provided, the invention comprises the use of acomplementary expansion turbine 214, as illustrated in FIG. 8, whichbleeds off the air produced in excess by the compressor 201 and whichthus recovers the excess mechanical energy consumed by the compressor.The expanded air can be used as the oxidant for a thermal application.

The gas-turbine blades are generally cooled by means of air from the aircompressor 201 flowing through the blades. Thus, with the thirdmodification to be provided in the case of application of the invention,the cooling air is replaced by steam in a lesser quantity. This allowssavings to be made on this cooling air and prevents the internalcombustion caused by the combustible gas in the turbine, this combustionnot being designed for the conventional machines.

Furthermore, the power released by the turbine is significantlyincreased given the increased volume of gas, the gas having a markedly,approximately 20%, lower density, and the base parameters, especiallythe pressures and temperatures, remain more or less the same. Moreover,it will be necessary to increase the power of the mechanical receiver orof the alternator in order to absorb the additional power.

All these conversions according to the invention on an existingindustrial turbine lead to a total net power which is more than doubled,taking into account the power recovered from the air-expansion turbineand the increase in the power of the turbine.

Table 2 gives the performance characteristics of a conventionalindustrial gas turbine adapted according to the invention to therepowering of a steam-type thermal power station having a power of 240MWe.

The method of converting industrial gas turbines according to theinvention is quite advantageous in the case of adaptation in steam-typethermal power stations operating in energy/heat cycle mode, with a powergain ranging from 40 to 50%.

However, this adaptation requires conversions to be carried out on theoriginal gas turbine.

Likewise, the teachings of Table 3 confirm that the specific power ofthe turbine is considerably increased, even more than doubled, therebymarkedly reducing the manufacturing cost. The total quantity of air tobe compressed is close to the stoichiometric ratio instead of threetimes the ratio in the case of known advanced turbines.

Table 3 gives the performance characteristics of such a turbineoperating in gas/steam combined-cycle mode and in gas/air/steamtriple-cycle mode.

TABLE 3 Gas/steam Gas/air/steam Turbine inlet temperature (° C.) 12501250 Compression ratio  45  45 Turbine outlet temperature 1050 1050Temperature for secondary cycle 1050 1050 Temperature for tertiary cycle—  525 P/T steam cycle: pressure 120/40/6  40 temperature 560/560  450Pressure, air cycle — 40/6.8 Temperature, air cycle —  950 Fuel, in MWth 100  100 Gas turbine net power  40  40 Air cycle net power —    15.6Steam cycle net power  21    9.4 Total net power, in MW cl  61  65 Netconversion efficiency     0.65     0.65

The third application relates to the partial-oxidation gas turbine ofspecific design according to FIG. 16.

A specific gas turbine according to the invention is composed of an aircompressor 310 with one or two stages, 311, 312, having, in the case oftwo stages, intermediate cooling by injection of reaction water 315.

A catalytic partial-oxidation reactor 307 of specific design, alreadydescribed in the second application above, is provided. In the reactor307, high-pressure air reacts by partial oxidation with the fuel andsteam which are injected at high pressure. The reaction gas coming fromthe high-pressure reactor 307 and at a controlled temperature isexpanded in the turbine 303. The gas from the reactor 307 is a fuel andits CO and H₂ concentration is high.

When the turbine 303 is operated at a temperature greater than 1000° C.,it is necessary to cool the stator blades 313 and the rotor blades 314.According to the invention, this cooling is achieved in a conventionalmanner by internally injecting air into the blades so as thus to ensurethat the blades are at a moderate temperature. This cooling air expelledin the turbine 303 reacts with the gas from the reactor 307 andparticipates in the gradual combustion thereof.

The expansion of the gas therefore proceeds isothermally, depending onthe chosen operating parameters of the turbine 303, especially thetemperature, pressure and quantity of steam added to the reaction. Thegas expelled by the turbine 303 is completely burnt and is available ata very high temperature. This subsequently facilitates the beneficiationof its energy potential.

The optimum choice of these parameters steers the system towards highpressures, of between 40 and 60 bar.

The cooling air comes from the air compressor 310 and is taken, at therequired pressure, via internal ducts 340, 360 to the rotor blades 314and via external ducts 380 to the stator blades 313.

The present invention greatly improves the known performancecharacteristics of the most advanced gas turbines, namely an efficiencyof direct conversion into mechanical energy ranging from 0.40 to 0.45,instead of the known 0.35-0.38 range, and a combined-cycle conversionefficiency ranging from 0.62 to 0.65, instead of the known 0.50-0.55range. Furthermore, it is apparent from Table 3 that the operatingconditions, especially the turbine inlet temperature, are markedly lessdrastic from a technological standpoint.

The systems in which the partial oxidation of the combustible gas isincorporated are complex, and even more complex to manage than thecombined systems which are in operation. They are characterized by anarrow range of permissible temperatures at the entry to the catalyticbed and in the latter, notwithstanding the variations in load, in termsof mechanical power and in terms of heat, both from the quantitystandpoint and from the thermal-level standpoint. The Belsim softwareand methodology (validation, parametric identification, simulation,optimization and optimum operation) are applied and all this computertechnology will be adapted in the context of the invention to partialoxidation.

FIGS. 17 to 20 now illustrate diagrammatically an entire assembly ofmeans for implementing the present system, the basic elements of whichare derived from the experimental steps in the implementation of thepartial-oxidation technology applied to gas-turbine cycles, i.e. in theimplementation of the invention as described above.

Initiation of the catalytic reactions constitutes, in itself, acapricious step. This is because it depends on the catalyst at the topof the catalytic bed and on the composition of the reaction gases. Inaddition, once the initiation front has been created, it does notnecessarily become stable, as it can migrate longitudinally. Undercertain operating conditions and in transient states, carbon depositshave been observed, these reaching a level so as to create unacceptablepressure drops. For some catalysts, the phenomenon occurs over theentire length of the catalytic bed. Before industry got round to usinghydrogen, the quantities of steam necessary for preventing carbondeposition was too great to ensure the best performance of the entiresystem. This is because, although it is well known that injecting steaminto a gas turbine increases its power, as, for example, in verticaltake-off aircraft, this additional power is only acquired at the expenseof a low calorific value yield for the fuel. Although it is accompaniedby an increase in the number of moles, the reforming reaction betweenthe gaseous fuel and the steam is endothermic. Consequently, the molarratio of oxygen to carbon must increase in order to deliver theadvantage of additional heat and this partially prevents the increase inthe number of moles due to partial oxidation.

The molar ratios defined by the expressions

R₁=O₂/C, R₂=H₂O/C and R₃=H₂/C

are typically, within the context of the invention, limited to 0.55<R₁<0.75, 0.8<R ₂<1.4 and 0.03<R₃<0.15, respectively.

The ratio R₁ will be between limits which are less than those mentionedabove in the case of the use of enriched air or of oxygen as theoxidant.

The aforementioned conditions may be obtained by recycling some of theoutput gases of the exhaust turbine or of the partial-oxidation reactor,the fuel flow being premixed with steam. The latter is produced byindirect exchange with the combustible effluent of the power turbine, orcomes from the steam mains of the industrial site.

An alternative mode of operation consists in bleeding off some of thefuel and in mixing it with the steam, or with some of it, so that theratio R₂ is sufficiently high to eliminate the danger of carbondeposition. This involves a known primary reforming operation which iscombined, according to the present invention, with a partial-oxidationgas-turbine cycle. The operating conditions of this reforming reactorare such that its effluent contains the necessary quantities of steamand hydrogen. The heat supplied to this endothermic reactor will comefrom chemical regeneration within the cycle itself, or from an externalsupply on the industrial site.

Laboratory tests have indicated that the quality of the reaction gasesis considerably improved by adding hydrogen to the reaction gases,improving the H₂/CO ratio on the output side of the reactor, which ratiois thus between 1 and 2 and may approximate the theoretical value of 2.

These same tests have also demonstrated that adding hydrogen allowsstricter control of the temperatures within the catalytic masses bysignificantly reducing the variations therein, these being much greaterin tests performed without hydrogen.

The second complementary object of the basic invention results from theexperimentation. It has been possible to achieve an optimum profile,without too marked a hot spot, by using different layers of catalystsand, in some cases, using the same active material but in 10 differentconcentrations. Incorporation of this type of technological solutionwithin a cycle comprising one or more gas turbines had not hitherto beenenvisaged, and this proves to be preferable, indeed almost essential,for lasting operation of the entire system.

The third complementary object of the basic invention is founded onanalysis of the most modern technologies used for manufacturinggas-turbine blades.

The fourth complementary object of the basic invention derives from thecomputations for optimizing the gas-turbine cycle, this being consideredseparately or being incorporated into complex energy systems. Thisobject was demonstrated by making use of known methods for analysingenergy systems. The solution which resulted has not yet been applied inconjunction with the basic technology.

It is understood that the four additional objects may be applied to eachof the three preferred exemplary modes of application described above.

It should be understood that the scope of the present application alsoextends to the energy systems of the type described above which areincorporated into a line for the preparation of synthesis gas forchemicals, such as methanol and ammonia. In this case, theaforementioned ratios would consequently be influenced thereby,especially depending on the chemicals desired.

It should be understood that the present invention is also of value forcycles comprising one or more gas turbines supplied with products comingfrom the gasification of coal, propane/butane (LPG) or other gases, suchas those used in refineries.

Partial oxidation is also applicable when it takes place not only usingair but also using oxygen-enriched air or using oxygen.

In FIGS. 17 to 20, the arrow denoted by the reference A indicates theair entering the system in the direction of flow denoted by the arrow F.The arrow denoted by the reference G indicates the entry of the gasesinto the combustion chamber 102, the reference H indicating the entry ofthese into the element 107 and 207. J represents the sum G+H, Srepresents the steam inlet and H₂ the hydrogen inlet, and K representsthe effluents from the turbine 243.

What is claimed is:
 1. A method of generating power energy, comprisingthe steps of: (i) introducing a first combustible gas into a catalyticreactor; (ii) submitting said first gas in said catalytic reactor to apartial oxidation reaction by an oxygen-containing gas in the presenceof steam injected upstream of said catalytic reactor and of apredetermined quantity of hydrogen acting as an initiating agent, forproducing a second combustible gas at a controlled high temperature; and(iii) using said second combustible gas from said catalytic reactor fordriving a power turbine to generate power energy.
 2. The method asclaimed in claim 1, wherein the hydrogen is provided depending on atriplet of molar ratios at a catalytic reactor inlet defined by theexpressions below: R₁=O₂/C; R₂=H₂O/C; R₃=H₂/C in which each of saidmolar ratios has a predetermined value, which is between 0.55 and 0.75,between 0.8 and 1.4 and between 0.03 and 0.15, respectively.
 3. Themethod as claimed in claim 2, wherein the molar ratio defined by theexpression H₂/CO at the outlet of said catalytic reactor is between 1.5and 2 and preferably fairly close to
 2. 4. The method as claimed inclaim 2, wherein the hydrogen is obtained from the system itself withpartial recycling of the gases collected downstream of said reactor,said gases being premixed with steam.
 5. The method as claimed in claim3, wherein the hydrogen is obtained from the system itself with partialrecycling of the gases collected downstream of the said reactor, saidgases being premixed with steam.
 6. The method as claimed in claim 1,wherein said partial oxidation reaction is achieved using a multi-layercatalyst comprising at least a first non-active layer and a secondactive layer.
 7. The method as claimed in claim 6, wherein use is madeof an active layer comprised of sub-layers of different types.
 8. Themethod as claimed in claim 6, wherein use is made of an active layercomprised of sub-layers having different activities and/or differentconcentrations.
 9. The method as claimed in claim 6, wherein use is madeof an active layer that is arranged on a support comprised of refractorymetals.
 10. The method as claimed in claim 1, wherein saidoxygen-containing gas is preheated within a temperature range of between400° C. and 500° C. approximately.
 11. An apparatus intended to generatepower energy, said apparatus comprising: gas compressor means foraccepting a gas containing oxygen for producing compressed gas; acatalytic reactor adapted for being fed by a mixture of a firstcombustible gas, said compressed gas, steam injected upstream of saidcatalytic reactor, and a predetermined quantity of hydrogen as aninitiating agent, for producing a second combustible gas at a controlledhigh temperature as a result of the partial oxidation reaction of saidfirst combustible gas by said oxygen-containing gas; and a power turbinefor being driven by said second combustible gas delivered by saidcatalytic reactor, said power turbine generating power energy.
 12. Anapparatus as claimed in claim 11, wherein the catalytic reactor includesa multi-layer catalytic mass comprised of at least a non-active layerand an active layer.
 13. An apparatus as claimed in claim 12, whereinsaid active layer is comprised of sub-layers having different typesand/or having different activities and/or different concentrations. 14.An apparatus as claimed in claim 11, wherein said power turbine hasblades coated with a catalytic coating.
 15. The method as claimed inclaim 6, wherein use is made of an active layer comprised of successivelayers of different types and/or different activities.
 16. The method asclaimed in claim 6, wherein use is made of an active layer comprised ofsuccessive layers of the same active material in differentconcentrations.
 17. The method as claimed in claim 6, wherein use ismade of a non-active layer that is arranged on a support comprised ofrefractory metals.
 18. An apparatus as claimed in claim 12, wherein saidactive layer is comprised of successive layers having different typesand/or having different activities.
 19. An apparatus as claimed in claim12, wherein said active layer is comprised of successive layerscomprised of same or similar active materials in differentconcentrations.
 20. An apparatus as claimed in claim 12, wherein saidnon-active layer is arranged on a support comprised of refractorymetals.
 21. An apparatus as claimed in claim 12, wherein said activelayer is arranged on a support comprised of refractory metals.
 22. Anapparatus as claimed in claim 11, further including an aeroderivativeturbine adapted for including and operating said gas compressor means,said catalytic reactor, and said power turbine.
 23. An apparatus asclaimed in claim 11, further including an industrial gas turbine adaptedfor including and operating said gas compressor means, said catalyticreactor, and said power turbine.
 24. An apparatus as claimed in claim11, further including an isothermal gas turbine adapted for includingand operating said gas compressor means, said catalytic reactor, andsaid power turbine.